System and method for invocation of services

ABSTRACT

A system and method for enabling the interchange of enterprise data through an open platform is disclosed. This open platform can be based on a standardized interface that enables parties to easily connect to and use the network. Services operating as senders, recipients, and in-transit parties can therefore leverage a framework that overlays a public network.

The present application claims priority to Provisional Application No.60/278,440, entitled, “System and Method for Routing Messages BetweenApplications, ” filed Mar. 26, 2001, which is incorporated herein byreference in its entirety.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a system and method for messagerouting. More specifically, the present invention relates to a messagerouting network for routing messages between applications.

2. Description of the Related Art

Corporate reliance on technology has become more complex and morepervasive. increasingly, companies are identifying opportunities toextend their core business or cut costs using the Internet. Both trendshave put increasing priority on integrating disparate businessapplications. For this reason, enterprise application integration (EAI)has emerged as a solution for allowing information technologydepartments to build bridges that are designed to unify their legacysystems into a single enterprise application. Ideally, the creation ofthis single enterprise application would not require sweeping changes tothe underlying structures.

EAI suppliers can be viewed in four categories, by decreasing level ofapplication independence: business process level integrators, processflow automation, data integration tools and data transport. Businessprocess EAI offers a number of advantages over traditional middlewaresolutions for integrating enterprises. First, business process EAI isalleged to be application independent, allowing it to be used in anyheterogeneous environment with a greater degree of reuse. Second, at itshigher level of abstraction, business process EAI does not require usersand implementers to have a detailed knowledge of each of the underlyingtechnologies.

As many EAI vendors have experienced, the practice of releasingcustomized connectors (or adapters) far each specific enterprisesoftware package has not proven to be scalable. Scores of adapters needto be built for each vendor (for example, Oracle Corporation of RedwoodShores, Calif., SAP AG of Waldorf, Germany, and PeopleSoft Inc. ofPleasanton, Calif.,). As each supplier releases new versions of theirsoftware, EM vendors find themselves unable to gain traction under theburden of supporting their existing adapters.

Notwithstanding the benefits of EAI, the software costs and resourceinvestments of EAI prevent small-to-medium enterprise (SME) customersfrom embracing EAI solutions. For SMEs, reliance on application serviceproviders (ASPs) represents an increasingly attractive alternative.

The ASP market is one of the fastest growing segments of the softwareindustry. ASPs make enterprise applications (e.g., human resourcesadministration, recruiting, travel and expense management, sales forceautomation) available to customers on a subscription basis. Thoseapplications are fully managed and hosted by the ASP, providingsignificant cost savings to enterprises.

Some ASPs merely host and manage third-party packaged software for theircustomers (“managed hosters”). Others build new applications from theground up to take advantage of the benefits and cost-savings of Web(“webware providers”). Webware providers enjoy the profit margins andoperational scalability of consumer Web companies like eBay Inc. of SanJose, Calif., and Yahoo! Inc. of Sunnyvale, Calif., while at the sametime offering the feature sets of complex enterprise softwareapplications such as software applications by PeopleSoft and SiebelSystems Inc. of San Mateo, Calif.

SUMMARY OF THE INVENTION

In accordance with the present invention, the interchange of enterprisedata is supported through an open platform. This open platform can bebased on a standardized interface that enables services to easilyconnect to and use the message interchange network. Services operatingas senders, recipients, and in-transit parties can therefore leverage aframework that overlays a public network.

BRIEF DESCRIPTION OF THE DRAWINGS

The foregoing and other features and advantages of the invention will beapparent from the following, more particular description of a preferredembodiment of the invention, as illustrated in the accompanyingdrawings.

FIG. 1 illustrates a message exchange network.

FIG. 2 illustrates components in a message exchange network.

FIG. 3 illustrates a request response pattern.

FIG. 4 illustrates a message flow sequence.

FIG. 5 illustrates an embodiment of a message exchange network.

FIG. 6 illustrates a provisioning process.

DETAILED DESCRIPTION

An embodiment of the invention is discussed in detail below. Whilespecific implementations are discussed, it should be understood thatthis is done for illustration purposes only. A person skilled in therelevant art will recognize that other components and configurations maybe used without departing from the spirit and scope of the invention.

In accordance with the present invention, the interchange of enterprisedata is supported through an open platform for enterprise applicationintegration (EAI). This open platform overlays a public network (e.g.,the Internet) and does not require business entities to heavily investin specialized software and resources. As will be described in greaterdetail below, the present invention enables the provision ofextra-enterprise application integration as a service. This servicefacilitates EAI efficiently and affordably to the businesses that needit the most (i.e., the small- and medium-sized enterprise (SME) market).More generally, the open platform of the present invention can be usedto support services provided by business-to-business (B2B) enablers,system integrators, and other node enablers.

FIG. 1 illustrates a high-level overview of a message interchange system100 according to the present invention. Message interchange system 100includes a message interchange network 150 that enables SMEs 110-m,webware ASPs 120-n, and in-transit processors (ITPs) 130-p to connect toone another, integrate business processes and applications, and exchangedata for mission-critical business functions. In general, ITPs 130-p areoperative to process messages that are in-transit from a sender to arecipient. ITPs 130-p can be designed to perform a variety of functionssuch as data transformation, enrichment, cross-reference ID mapping,filtering, credit scoring, or the like.

A directory (not shown) includes a list of all SMEs 110-m, webware ASPs120-n and ITPs 130-p that can be accessed via message interchangenetwork 150. Only publicly available services (i.e., those services thatorganizations register as accessible by any user of the network) areviewable in the directory.

In general, all applications that are connected to message interchangenetwork 150 can be referred to as a service. In the illustratedembodiment of FIG. 1, applications owned by SMEs 110-m, webware ASPs120-n and ITPs 130-p can each be referred to as services. Each serviceis owned by an organization, and an organization can have any number ofservices connected to message interchange network 150. The messageexchange within message interchange network 150 is therefore betweenservices.

In one embodiment, services that receive messages can take a set ofarguments that further define the intended action the service willperform on a received message. For example, a service may receive thename of an operation, or may permit configuration parameters. In thisenvironment, the service would provide a means (e.g., through a URL todocumentation) for message composers to know about arguments accepted bythe particular service. The message composer can then include selectedarguments as a part of the service declaration in a message.

As described, services registered with message interchange network 150represent applications that send or receive messages. An organizationmay, however, wish to create virtual services which act as proxies toother services. For example, a business X may have a relationship withbusiness Y such that messages sent to business X's service areredirected to business Y's service. Services can implement redirectionthrough routing scripts that map invocations of the service toinvocations of another service, including redirection of replies.

For each service registered by an organization with message interchangenetwork 150, there are a number of properties and permissions that canbe associated with the service. Examples include a unique serviceidentifier, authentication information, mode of message delivery,windows of time during which messages are accepted, URL address ofservice, permission to invoke other services to act on a message, andrules that modify the invocation of services. These properties andpermissions affect the routing of messages from or to the service.

FIG. 2 illustrates the primary functional components that operate withinmessage interchange system 100. The five primary functional componentsinclude service software development kit (SDK) component 210, webinterface component 220, message router component 230, repositorycomponent 240, and billing component 250.

SDK component 210 serves as a foundation for supported development ofclient applications that interface with message interchange network 150.Owning organizations can use SDK component 210 for custom integrationwith their software applications. As would be appreciated, SDK component210 is not required to enable a service to access message interchangenetwork 150. A service can use any development tool or process thatwould enable the service to leverage the application programminginterface (API) that is supported by message router component 230.

In general, SDK component 210 enables the provision of an interface thatwould be available on most common platforms, and in most popularlanguages. In this manner, SDK component 210 abstracts away the complextechnical requirements of transferring messages using messageinterchange network 150.

It is a feature of the present invention that SDK component 210 need nothave any business logic built into it. SDK component 210 can be used todevelop plug-ins to shrink-wrapped applications, thereby greatlyreducing development time. As would be appreciated, SDK component 210can provide convenient libraries and utilities that a service mayoptionally use to facilitate the (1) creation and reading of messagesconforming to the message router component API, and (2) authenticationof users of message interchange network 150.

Repository component 240 is the primary database of message interchangenetwork 150. Repository component 240 includes information on customerprofiles, message logs, and directories. As will be described in greaterdetail below, message router component 230 uses repository component 240to retrieve customer and application information that affects messagerouting. Message router component 230 also writes message loginformation to repository component 240 about messages that areprocessed through message interchange network 150.

Billing component 250 uses the message log information in repositorycomponent 240 to derive actual usage of message interchange network 150by customers, and handles the invoicing and payment collection fromcustomers. It is a feature of the present invention that the billingwithin message interchange system 100 can be based upon actual customerusage of message interchange network 150. For example, billing component250 can charge customers based on a per transaction basis. In oneembodiment, the per-transaction cost is based on the size of themessages being processed. As would be appreciated, these per transactioncosts can be assessed to parties in a variety of ways. For example, thecosts can be assessed against the originator of the message, theintermediate services, the recipient of the message, or any combinationof those parties. This billing flexibility is in sharp contrast toconventional EAI solutions that generate revenue through softwarelicense fees.

Web interface component 220 is the front-end component of messageinterchange network 150. Web interface component 220 interfaces directlywith users by enabling login, registration, account maintenance,directory lookup, rules configuration, reporting, billing, and customersupport functionality. The web interface provides online forms for dataentry and can perform preliminary validations on the data. Through webinterface component 220, the user can also perform queries againstrepository component 240 for directory lookups or reporting.

It is a feature of the present invention that message interchangenetwork 150 is an open network architecture that not only facilitatesthe easy introduction of services into the network, but also enablesbusinesses to access a robust suite of services via one connection tothe message interchange network 150.

As noted, message router component 230 provides the core function ofmessage routing and delivery within message interchange network 150. Inone embodiment, message router component 230 is implemented as anInternet-based message exchange service that provides a transport levelmessaging service. In other words, message router component 230 need notbe aware of the application semantics of a message exchange.

Thus, it is a feature of the present invention that message interchangenetwork 150 need not inherently provide business process modeling. Thisis in contrast to conventional EAI solutions that may require acontinual traversal up and down a protocol stack in routing a messagefrom a sending service to a recipient service. For example, if theprotocol stack included transport, routing, transformation, and workflow layers, then each message exchange segment may require analysis andprocessing at each layer to determine the next service (intermediate orfinal) that should receive the message.

As noted, services can post messages to and retrieve messages frommessage router component 230 using an API. This provision of astandardized interface enables parties to easily connect to and usemessage interchange network 150 without being restricted in the type ofmessage content.

In one embodiment, the protocol for posting and retrieving messages withmessage interchange network 150 is the Simple Object Access Protocol(SOAP). The SOAP messaging protocol defines a mechanism to pass commandsand parameters between HTTP clients and servers. Through this standardobject invocation protocol, HTTP is used for transport and XML is usedfor data encoding. The SOAP messaging protocol does not rely on the useof particular operating systems, programming languages, or object modelson either the server side or the client side. As would be appreciated,other protocols can also be supported by message interchange network150.

It is a feature of the present invention that while the message headeruses extensible markup language (XML) syntax, the message body canaccommodate any type of data, whether it be text or binary, encrypted orunencrypted. If the message body is also in XML form, then the messagebody can opt to use a schema based on an industry standard such asebXML, BizTalk, RosettaNet, OAGIS, or any other suitable standard.

In one embodiment, message exchange through message interchange network150 is asynchronous. Recipient services can be configured to pollmessage interchange network 150 for incoming messages, or, if they havetheir own server, can have message interchange network 150 push messagesto them.

After a sending service posts a message to message interchange network150, one or more in-transit services 130-p can operate on the messagebefore it reaches the recipient service. In-transit services can performuseful operations on messages, such as data transformation, enrichment,cross-reference ID mapping, filtering, credit scoring, or the like.Through the standardized interface, in-transit services 130-p canindependently join the message interchange network 150 and operate onmessages. This flexibility encourages independent third parties to buildservices that can be plugged into message interchange network 150. It isa feature of the present invention that such an open network wouldencourage third parties to market a data service that generates revenuebased upon the level of utilization of the service.

As noted, in-transit services can be included in a message path thatbegins at a sending service and terminates at a recipient service. Aswill be described in greater detail below, sending services canexplicitly specify a set of services to operate on a given message. Inaddition, recipient services can specify services that should operate onmessages before delivery to the recipient service. In one example, arecipient may always want messages to pass through a filtering serviceto screen out messages from unknown senders.

Messaging through message interchange network 150 can be as secure asthe participants desire. Each service registered with messageinterchange network 150 can specify a security policy declaringencryption and authentication levels for message interchange network 150to enforce. For messages that flow through in-transit services, a sendercan also specify the permissions for each in-transit service to accessor operate on parts of the message.

In one embodiment, message interchange network 150 uses the secure HTTPSprotocol to support secure transport connections when a service posts amessage or polls for messages, and when message interchange network 150pushes messages to a client server. Authentication can be based oneither username/password or certificates.

SSL encryption as part of HTTP can be used to provide data protectionduring message transmission over the public Internet. In general, thislevel of protection is sufficient for most situations. Services can,however, perform their own extra encryption of message documents to keepthem private even from message interchange network 150. Services thatadd extra encryption should ensure, however, that all services thatoperate on the message documents have the necessary keys to decrypt thedocuments.

As is well known, the authentication protocol of SSL includes a server'spresentation of a certificate to clients. Accordingly, messageinterchange network 150 presents a server certificate to services thatconnect for posting or polling. The connecting service has the option ofthen providing either a username/password or certificate for messageinterchange network 150 to authenticate the service. The form of clientauthentication is a configuration option within the profile messageinterchange network 150 maintains for each service.

When message interchange network 150 pushes messages to a service, theservice's server should present a server certificate to messageinterchange network 150 for authentication of the service. For thereverse authentication, the service can then require either ausername/password or certificate from message interchange network 150.Again, that option can be configured in the profile information messageinterchange network 150 maintains for the service.

As a message flows through a selection of services on the way to therecipient service, and as the recipient service's response returns tothe sending service, message interchange network 150 maintains an audittrail of all operations on the message and all services that touched themessage. The audit trail serves several purposes. First, it enablesmessage interchange network 150 to reconstruct the message history inthe case of queries on the message trail. Second, it allows messageinterchange network 150 to compile a usage report for any service forreporting and billing purposes.

Having described the general framework of message interchange network150, a more detailed description of a message transaction lifecyclewithin message interchange network 150 is provided with reference toFIG. 3.

In this framework, a message can be embodied as a self-containedcollection of information to serve a particular purpose, such as arequest, a response, a notification, or an acknowledgement. As noted,message interchange network 150 can generally be agnostic about thecontent of a message other than header information that affects routingof the message.

In one embodiment, request, response, and notification messages can bedefined. A request message expects a subsequent response message fromthe recipient(s) to be returned to the sender. Request messages mayrepresent inquiries, but might also represent update requests that onlyexpect a return status response. If an error occurs in routing a requestmessage, message interchange network 150 returns an error responsemessage to the sender.

A response message is issued by a recipient of a request message. Theresponse message references the original request message. Failure of theresponse message may result in an error response message being returnedto the sender of the original request message.

A notification message is a one-way message. No response to thenotification message is expected back to the sender. Message interchangenetwork 150 can regard any response message referencing a notificationmessage as an invalid message. If a notification message fails, no errormessage is returned to the sender.

As would be appreciated, further messages can be defined for messageinterchange network 150. For example, a cancel message can also bedefined, wherein the cancel message is used by the sender to cancel aprevious message.

The operation of these messages is now described with reference to therequest/response illustration of FIG. 3. This illustration demonstratesa typical example of a sending service 310, such as an enterprise,making an inquiry to a recipient service 360, such as a webwareprovider. In one embodiment, a sender's application 312 that connects tomessage interchange network 150 is a desktop application. In anotherembodiment, a sender's application 312 that connects to messageinterchange network 150 is an enterprise server, or an EAI package.

The first step in the message transaction process is the creation of amessage. In one embodiment, a sender formats the messages to conform toan XML schema for messages. This XML schema prescribes the format formessage headers while allowing any kind of data to be included in themessage body (or payload). As part of message construction, sendingservice 310 specifies the recipient service(s) 360 of the message. Inone embodiment, a recipient service's name includes an organization anda specific service provided by that organization. The service name canbe generally represented in the message via a globally unique ID.

The actual set of elements contained in a message depend on whether themessage is being posted or delivered. In one embodiment, a messageincludes a header element, a body element and/or attachments. In oneembodiment, the attachments are based on multi-part MultipurposeInternet Mail Extensions (MIME).

An embodiment of a message that includes header and body elements isincluded in Appendix A. In this example, the cardinality of elements isindicated as ‘?’ or {0:1} for an optional instance; ‘*’ or {0:N} forzero or more instances; and ‘+’ or {1:N} for one or more instances. Nosymbol or {1} represents a required single instance. As would beappreciated, the actual message format can differ depending on theprotocol. In particular, protocols other than the SOAP protocol can beused.

The header element includes routing and invocation information. Theheader as posted by a sending service is often modified by messageinterchange network 150 for delivery to the receiving service.

The body element includes the documents the sender is sending to therecipient(s). These documents can also be operated upon by one or moreservices. As noted, the documents can be in the form of XML or any otherrepresentation, including text, binary, etc. In one embodiment, all orpart of the documents that are being sent are included in an attachmentto the message.

While messages will typically have a similar overall structure, theactual composition of elements can differ between the various messagetypes and between messages as posted and as delivered. For example, someelements in a sent message can be changed or not be included in themessage as delivered, such as elements particular to constructing aroute. Some elements can also be inserted only in the message asdelivered, such as identifier elements.

If the sending service wishes to have the message routed through anyservices before delivery to the recipient service(s), the sendingservice can specify an explicit sequence of services that should operateon the message. The sender can also implicitly include services in theroute for a message through the specification of routing scriptsassociated with the defining service. Routing scripts are described ingreater detail below.

After a message is constructed, the message is posted to messageinterchange network 150. This process is illustrated in FIG. 3 as theposting of a message by application 312 to message post interface 324.As noted, in one embodiment, the posting of a message is performed usingthe SOAP messaging protocol.

If sending service 310 posts a message that does not have well-formedXML, the message posting is rejected and an error response is returned.In general, messages can be rejected for a variety of other reasons. Forexample, a message can be rejected if the service indicated in themessage header as the sender is not the same as the actual sender of themessage, the message is a duplicate posting of a previous message, aservice attempts to reply to a message for which it was not a recipient,or a response message does not reference a prior message.

In one embodiment, each message posted by a service can have a uniquehandle assigned by the service to identify the message. This uniquehandle can be used to provide a means for message interchange network150 to detect duplicate postings of the same message. Duplicate postingscan occur in the case of failure recovery by the service. In oneembodiment, if a service desires that message interchange network 150should reject duplicate postings of a message, then the service couldprovide unique handles for messages and set a “potential duplicate” flagin messages that may be a duplicate posting. It should be noted thatregardless of whether or not a service provides a unique handle for amessage, message interchange network 150 can assign a globally uniquesession identifier to each posted message.

After a message is posted, message interchange network 150 routes themessage to the recipient service(s) 360. The routing of the message isbased upon a route calculation by message interchange network 150. Thecalculated route includes all intermediary services 350 that arescheduled to operate on the message en route to recipient service(s)360. The calculated route can be based on routing instructions specifiedexplicitly in the message header and/or on routing scripts pre-definedby the sending service 310, recipient service 360, or any in-transitservices 350 that have been included within the calculated route.

In general, routing scripts define a procedure for enablingdetermination of at least part of a route. This procedure can be basedon any type of criteria. For example, a procedure can be defined thatdetermines a next destination of a message based on the existence of oneor more attributes of the message. In another example, a procedure canbe defined that effects a determination based on the comparison of oneor more attributes of the message to a reference value. In yet anotherexample, a procedure can be defined that effects a determination basedon pattern matching (e.g., regular expression matching). As would beappreciated, routing scripts can embody any of a variety ofcriteria-based procedures.

Routing scripts can specify a sequence of services that operate oneither inbound or outbound messages for a service. As noted, in-transitservices may themselves have routing scripts requiring processing byother services. Therefore, the route calculation can be recursivelydefined based upon routing scripts specified by all services thatinteract with the message.

In one example, the sending service 310 may specify a routing scriptthat requires a cross-reference mapping service to be included in thecalculated route whenever sending service 310 sends a message torecipient service 360. In another example, recipient service 360 mayspecify a routing script that requires that any incoming requestmessages must first pass through a filter service to block messages froma list of sending services 310.

Routing scripts enable sending services to include services into themessage route without having to explicitly specify the services in themessage itself. Also, routing scripts enable recipient services 360 torequire services 350 to be in the calculated route, regardless of thesending service's route specification.

In one embodiment, a routing script is embodied as a routing rule. Arouting rule includes two parts: a condition and one or more resultantactions. The conditional part of a rule can be based on any elements orelement attributes in a message's header. Additionally, content-basedrouting can be supported through conditional rules based on attributesof an element in a message's body and/or attachments.

Every rule should have at least one condition. Conditions include anoperator and zero or more operands. Example operators include equals,notEquals equalsOneOf, lessThan, greaterThan, and exists operators. Inone embodiment, operators act on XML elements, XML attributes, or onother conditions.

From the standpoint of the element operators, XML elements containeither child elements or character data. Therefore, the operands for anelement comparison both represent the same type of content: eitherelements or character data. Character data can be in the form of astring, number, or date. Conditions involving elements that do notappear in the message will evaluate to false.

Attributes always have a type of character data, which can be string,number, or date. Many attributes are implicitly included in an XMLdocument with default values. Therefore, an attribute identified in acondition can refer to either an explicit or implicit attribute.Conditions involving optional attributes that do not appear in themessage will evaluate to false.

The usual boolean operators can combine conditions into more complexconditions. Condition operators act on other conditions. Examplecondition operators include AND, OR, XOR, and NOT condition operators.

The result of satisfying a rule's conditions is that an action will betriggered to modify the route for a message. Probably the most commonresult of a rule is to add one or more services into the route for amessage. Several rule actions can be defined, including but not limitedto an AddServiceAfter action, an AddServiceBefore action, an AddServiceaction, a Redirect action, a ChangeTopic action, and aStopRuleEvaluation action.

In an AddServiceAfter action, a service (other than a final recipientservice) can add a service after itself in the route. If this actionappears more than once in the action list for a rule, the service isadded such that the resultant service order is the same as the order ofactions.

In an AddServiceBefore action, a service (other than a sending service)can add a service prior to itself in the route. If this action appearsmore than once in the action list for a rule, the services are addedsuch that the resultant service order is the same as the order ofactions.

The AddService action is identical to either the AddServiceAfter actionor the AddServiceBefore action depending on the role the service haswith respect to the message. For message senders, the services are addedafter the sender; for message recipients, the services are added priorto the recipient; for in-transit services, the services are added priorto the including service. This action generally enables rules that areuseable by a service independent of role.

In a Redirect action, a service may wish to have the message redirectedto another service in its place as the receiving service for themessage. For example, a service may be a virtual service, and needs toredirect messages for that service to another service.

In a ChangeTopic action, if a first service includes a second serviceinto the route or performs a redirect for a third service, then thefirst service can also change the topic of messages sent to the secondservice or the third service. The topic change will only apply tomessages as delivered to the second service or the third service, andwill revert to the original topic for subsequent services in the messageroute.

The StopScriptEvaluation action terminates the evaluation of subsequentscripts for the same service. Script evaluation will then continue forthe next service in the route.

A service should maintain an evaluation sequence for the scriptsassociated with each role that the service can have with respect to amessage. That sequence determines the order in which the scripts forthat service are applied.

In one embodiment, scripts are evaluated in the following order: (1)scripts for the sender of the message; (2) scripts for services includedby the scripts for the sender (this is recursive); (3) scripts for therecipients of the message, in the order of recipients in the messageheader; and (4) scripts for services included by scripts for therecipients (this is recursive).

When multiple scripts for a service include services into a route, theorder of services in the route will follow the order of the scripts.That is, if script 1 inserts service A, and script 2 inserts service B,and if script 1 is evaluated before script 2, then service B followsservice A in the route.

In one embodiment, routing scripts are evaluated only once during theinitial calculation of the route for a message. The message headercontains the basic information to initially construct a route, such assending service 310 and recipient services 360. The message can alsocontain an explicit specification of a set of services to include in theroute. Once the route is constructed from the header information,routing scripts are applied to further elaborate the route.

In an alternative embodiment, at least part of the message route iscalculated after the physical routing of the message has begun. Dynamicrouting is described in greater detail below in the context of physicaland logical routing.

At the transport level, message interchange network 150 routes a messageto a service by delivering the message through the Internet to aphysical machine on which the service resides. That service operates onthe message and, if the message is a request, returns a response messageback through the Internet to message interchange network 150. Thesequence of message deliveries and responses between message interchangenetwork 150 and services represents the physical routing of a message.

Message interchange network 150 also provides a mechanism for a serviceto act on a message without the message being physically delivered tothe service over the Internet. This mechanism is enabled through thelogical routing of the message to the service. With logical routing, aservice can modify the routing of the message or modify the context ofthe message for delivery to the next service. Significantly, a servicecan be logically included in a message routing, without being includedas part of the physical routing of the message.

In one embodiment, logical routing of messages is implemented throughthe specification of routing scripts. As described above, a service candefine one or more routing scripts. These defined routing scripts arestored within message interchange network 150 and are processed todetermine what routing behavior should occur when a message is logicallyrouted to the service.

Logical routing can take place statically or dynamically. With staticlogical routing, a message is logically routed to all services prior toany physical routing. In other words, message interchange network 150logically routes the message to all services prior to the physicaldelivery of a message to any services. This logical routing isrepresented by the sequential evaluation of the routing scripts that aredefined by those services. As noted above, in one embodiment, therouting scripts are evaluated in the following order: (1) scripts forthe sender, (2) scripts for the services included by the sender(recursive), (3) scripts for the recipient, and (4) scripts for theservices included by the recipient (recursive).

In dynamic logical routing, the logical routing is not completed priorto the start of the physical routing. Rather, the logical routing takesplace in sequence with the physical routing of the message. The relationbetween logical routing and physical routing is described in greaterdetail below.

As noted, message interchange network 150 delivers a message logicallyto every service participating in a message's routing. Of thoseservices, some subset will also accept physical delivery of the message.

To illustrate this concept, consider an example where service A includesservice B into the message route. Service A can include service B intothe route either prior to itself in the route (provided service A is notthe originator of the message) or after itself in the route. In eithercase, message interchange network 150 would logically route the messagefirst to service A, which includes service B into the route. Messageinterchange network 150 then logically routes the message to service B,and after service B produces a response, message interchange network 150logically returns the response to service A. The point at which serviceA physically receives the message depends on whether service A includedservice B prior or after itself in the route. If service A includesservice B prior to itself in the route, then the order of physicaldelivery is first to service B then to service A. Conversely, if serviceA includes service B after itself into the route, then the order ofphysical delivery is first to service A then to service B. In the lattercase, the response from B is not necessarily physically delivered backto service A. Rather, it may be only logically delivered back to serviceA.

Services to which a message is logically routed do not necessarily haveto also physically receive the message. In the above example, service Acould have been logically routed, with physical delivery only to serviceB. Consider the following scenario. Suppose service X includes service Ainto the route and service A includes service B into the route. Thelogical routing of the message would proceed from service X to service Ato service B back to service A back to service X. Service A can choosenot to be included into the route for physical delivery, in which casethe physical routing of the message is from service X to service B.

In general, the act of routing a message (physically or logically) to aservice can be thought of as an invocation of the service. When aservice includes another service into the route of a message, theincluding service is effectively invoking the included service. Theinvocation of a service does not necessarily imply the physical deliveryof information to the invoked service. The logical routing of a messageis then the logical invocation of services. A route that includes aprogression of services including other services can effectively bemodeled as a progression of invocations.

In logical routing, each service is not only able to manage theinclusion of other services into the route but is also able to managethe context of those inclusions. From the standpoint of invocations, aninvoking service is able to set the context for the invocation. Aninvoked service can also set the context of its return.

It is a feature of the present invention that message interchangenetwork 150 effects context management on behalf of invoking services.As noted, while an invoking service can be logically included in amessage routing, it need not be included as part of the physical routingof the message. In general, message interchange network 150 persistentlystores contexts of a message, thereby enabling proper restoration ofcontexts upon return from an invocation.

In various embodiments, invocation context can include such informationas the identity of the invoker service, arguments to the invokedservice, a session identifier for the message, a topic for the message,billing responsibility for the invocation, or any other information thatcan be used by the invoked service. When a service is invoked, itreceives a context from its invoker. That invoked service can thenmodify, if desired, parts of the context when invoking yet anotherservice. Upon return from an invocation, message interchange network 150automatically restores the context of an invoker to the state prior tothe invocation. In one embodiment, the context of an invocation isincluded in the header information of the message delivered to aservice. In another embodiment, the context of an invocation is based onone or more parts of a message.

Responses from invocations also contain context, such as the completionor error status of the response. When a service receives a returnedresponse from an invocation, the context of the invoker is augmented bythe context of the response. That service can then optionally modify theresponse context when returning to its invoker. It should be noted thatjust as logical routing can occur either statically or dynamically,context propagation (for both invocation and response) can also occureither statically or dynamically.

The ability of services to manage the context of their invocationsprovides a way for services to assume a large degree of control over thescope of their participation in handling a routed message. For example,a service can choose to isolate its invoked services from being awarethat the invocation occurs as part of a broader message routing. Aservice can choose to assume responsibility for charges incurred bysubsequent nested invocations. A service can also choose whether or notto expose a received error condition up the invocation chain.

Message interchange network 150 can also use the invocation contexts totrack messages and determine responsibility for invocations. Based oninvocation contexts, message interchange network 150 can reconstruct thehistory of a message necessary for auditing and billing, as well as forreporting.

Having described a framework for logical routing and invocation ofservices, the description of the physical routing process is continuedwith reference to FIG. 3. In this example, it is assumed that staticlogical routing has produced a route for the message.

After deriving the route for a message, message interchange network 150validates the route. There are numerous conditions that can cause aroute to be invalid. For example, there may be routing permissionviolations or a service may be currently disallowed by messageinterchange network 150 due to, for example, the non-payment of usagebills.

If the route is determined to be invalid, then message interchangenetwork 150 rejects the posted message and may return an error to thesending service 310 either in the response to the posting call or in anerror message.

Message interchange network 150 routes the message to all services inthe calculated route. In the event of failure at any stage in therouting, message interchange network 150 aborts the message routing and,if the original message was a request, returns an error message back tosending service 310. For messages with multiple recipients, an error inthe routing to one recipient will not necessarily affect routing toother recipients. Errors during routing can occur due to severalcircumstances. For example, a message may fail to reach a recipientwithin the expiration time for the message, a service may fail to returna reply to a delivered message, or a service may return an error statusfor a message.

Message interchange network 150 sequentially delivers a message to eachservice identified in the message route. In FIG. 3, this process isillustrated as a flow of the posted message through message routingelement 340, and on to one or more services 350. In one embodiment,message interchange network 150 includes all of the message documents inthe message delivered to service 350, even if service 350 only expectsto operate on one document or documents of a particular content-type.Service 350 would ignore documents that it does not expect.

As noted, message interchange network 150 invokes in-transit services inthe same way as delivering a message to any sending or recipientservice. In general, a service does not necessarily need to be awarewhether it is being invoked as an in-transit service or as a recipientservice.

After processing the message, service 350 sends the results in aresponse message back to message interchange network 150. If service 350is unable to produce a valid result for its operation on a message, thenservice 350 may return an error code in its response message to messageinterchange network 150. If service 350 fails to respond to a receivedmessage, the message will ultimately expire, and message interchangenetwork 150 may return an error message back to the sending service 310.

Upon receipt of the response message from service 350, messageinterchange network 150 then routes the message to the next destination(e.g., another service 350) on the routing list. After passing througheach of the intermediate destinations on the routing list, the messageis then stored in queue 334 for recipient service 360. It should benoted that queues can also be associated with in-transit services 350.For simplicity, these queues are not shown in the illustrated embodimentof FIG. 3.

Application 372 in recipient service 360 can retrieve the message fromqueue 334 via message poll interface 328. In the poll mode, application372 periodically issues a call to message poll interface 328 to ask forany waiting messages. If there are queued messages waiting for deliveryto that service, then the one or more messages are returned in a reply.When making poll requests, a service can provide selectors on themessages to fetch. For example, a service can retrieve messages basedupon the sender, message type, topic, etc.

In an alternative embodiment, message delivery is enabled through a pushmode. In the push mode, the recipient would have its own server to whichmessage interchange network 150 can send messages. A service can specifya maximum number of tries, as well as the retry interval, for messageinterchange network 150 to send the message to the service beforeaborting pushed delivery. A service to which message interchange network150 pushes messages can also optionally poll for messages.

In the push mode, a service can also specify a delivery window in whichit will accept pushed messages. For example, a service might only acceptmessages between the hours of 1 AM and 2 AM.

As further illustrated in FIG. 3, a response message can be posted byrecipient service 360 to message post interface 326. The message is thenrouted through one or more services 350 prior to being stored in messagequeue 332. The message can then be retrieved by sending service 310through message poll interface 322. As noted, the return path would notnecessarily match the forward path.

In one embodiment, the sender of a message can specify a time by whichthe routing of a message must complete. If that expiration time passesbefore delivery of the message to it final destination, messageinterchange network 150 will abort further routing of the message. Inone embodiment, the final destination for a request message is thedelivery of a response message back to the original request sender. Inthis embodiment, senders of response messages cannot specify anexpiration since the response is considered part of the routing of theoriginal request message. If a request message expires, messageinterchange network 150 will return an error response back to thesender. If the sender does not specify an expiration time, then adefault message expiration time (e.g., 48 hours) can be used. It shouldbe noted that message expiration is not the same as document expiration.Document expiration is associated with a specific document and indicateshow long the document's information is valid.

As part of the message delivery process, message interchange network 150logs all posted messages, including invalid messages. For each message,message interchange network 150 logs relevant information to track thehistory of the message. Message interchange network 150 also maintains acorrelation between messages. That is, for request messages, messageinterchange network 150 associates the log of the response message(s)with the log of the request message.

In one embodiment, logged information can include the message header,the calculated route for the message (unless route calculation fails),the status of route validation, the size of the message at each stage ofthe route, and the routing history, including the status for eachservice along the message's route. The status values for each servicedepends on the role of the service.

Message interchange network 150 correlates all messages for the samemessage transaction. That is, for request messages, message interchangenetwork 150 associates the log of the response message(s) with the logof the request message. Similarly, if a message causes an error message,then message interchange network 150 associates the log of the generatederror message with the log of the original message.

Having described a general framework of operation of message interchangenetwork 150, an example message sequence is provided to illustrate theconcepts described above. In the example message sequence illustrated inFIG. 4, a message is routed from sender 402 to recipient 404. Duringthis message routing, the message is also passed through in-transitservices 406, 408, 410, and 412. The specific operation of services 406,408, 410, and 412 will become apparent through the description of themessage operation sequence.

In the illustrated example, sending service 402 represents a businessnamed MyBiz.com. MyBiz.com desires to send a purchase order to The AcmeCompany, which operates as recipient service 404. Before being deliveredto The Acme Company, the purchase order message is sequentially routedby message interchange network 150 through Transmatics (XSLT) service406, XpandiCo service 408, Transmatics (replaceelement) service 410, andKeepEmOut.com service 412.

In general, services 406, 408, 410, 412 are operative to performtransformations, enrichment, and filtering functions on the purchaseorder message. In the present example, Transmatics (XSLT) service 406 isoperative to transform address data in the message body, Xpandicoservice 408 is operative to augment a zip-code address, Transmatics(replaceElements) service 410 is operative to relate sets of values fromdisparate data sources, and KeepEmOut.com service 412 is operative tofilter messages for The Acme Company.

As noted, services 406, 408, 410, 412 can be added to a routing listbased upon routing scripts that are created for one or more of sendingservice 402, recipient service 404, or in-transit services 406, 408,410, 412. In the present example, services 406, 408, and 410 are addedto the route list in accordance with routing scripts defined for sendingservice 402, while service 412 is added to the route list in accordancewith routing scripts defined for recipient service 404. An exampleembodiment of the message sequence between services in the routing listis now provided.

As noted, in one embodiment, a message includes a header element, a bodyelement and/or attachments. In general, the header element includes thebasic delivery information for the message, and the bodyelement/attachments includes the document(s) the sender is sending tothe recipient. As would be appreciated, further message elements can bedefined. For example, in another embodiment, a message would includeheader, body, routing, and route trace elements. Here, the routingelement includes a listing of a sequence of services that should operateon the message prior to delivery to the recipient, and the route traceelement includes the routing history information.

Appendix B.1 illustrates an example of a message that is posted byMyBiz.com to message interchange network 150. As illustrated, themessage includes a header element at lines 4-17 and a body element atlines 18-28.

The header element at lines 4-17 includes elements To, From, andExpiration. To element also includes two Service elements, one of whichincludes the element Arguments. As illustrated, one of the Serviceelements identifies the recipient service “TheAcmeCompany/Supply,” theservice that is representative of recipient 404 in FIG. 4. The elementArguments provides parameters that further specify what the“TheAcmeCompany/Supply” service is to perform (i.e.,ProcessPurchaseOrder).

As illustrated, at line 14, the From element includes a serviceidentifier for MyBiz.com (i.e., “386b4520f489c217”). Finally, at line16, the Expiration element specifies a time by which the message shouldcomplete its routing.

The body element of the message is located at lines 18-28. In thismessage element, the purchase order data is included at lines 21-25. Aswill be described below, the purchase order data can be transformed andenriched by services in the routing list.

As noted, the sender can specify an explicit sequence of services thatshould operate on the message. The sender can also implicitly includeservices in the routing list for a message through the specification ofrouting scripts associated with the defining service. In the examplemessage of Appendix B.1, no services are explicitly identified in themessage. Rather, the services are included based on routing scripts thatare defined by the various services. In the present example, the routinglist includes, in order, Transmatics (XSLT) service 406, XpandiCoservice 408, Transmatics (replaceElement) service 410, and KeepEmOut.comservice 412.

The first service on the routing list is the Transmatics (XSLT) service406. In the present example, service 406 is included in the routing listbased upon a routing script defined for sender 402. Transmatics (XSLT)service 406 is a transformation service that uses the ExtensibleStylesheet Language Transformations (XSLT) language.

Generally, XSLT is a language for transforming XML documents into otherXML documents. XSLT is designed for use as part of the XSL, which is astylesheet language for XML. In addition to XSLT, XSL includes an XMLvocabulary for specifying formatting. XSL specifies the styling of anXML document by using XSLT to describe how the document is transformedinto another XML document that uses the formatting vocabulary.

In the present example, Transmatics (XSLT) service 406 is operative totransform data in the purchase order message. This transformation isillustrated in Appendix B.2, which shows the purchase order message asit is delivered to XpandiCo service 408 after being processed byTransmatics (XSLT) service 406. More specifically, the transformationoperation is illustrated upon comparison of the Address element at line25 of the message in Appendix B.1 to the Address element at lines 24-28of the message in Appendix B.2. In this transformation process, anAddress element including the entire address has been transformed intoan Address element that includes further child elements (i.e., Street,City, and Zip) directed to components of the Address.

As can be appreciated, this transformation process can be used to ensurethat the purchase order to be delivered to a particular recipientservice 404 is placed in the proper format. If other recipients requirea purchase order to appear in different formats, then furthertransformation operations can be defined and implemented by a serviceattached to message interchange network 150.

After the message is processed by Transmatics (XSLT) service 406, it isthen sent to the next service on the routing list. In this example, thenext service on the routing list is XpandiCo service 408.

As illustrated in Appendix B.2, the message delivered to XpandiCoservice 408 includes Header and Body elements that are similar to thecorresponding elements in the message that was posted by MyBiz.com.

The Header element in the message delivered to XpandiCo service 408 alsoincludes a Session element and a Token element. The Session element atline 4 includes a unique session identifier (i.e.,“34b9f6d0-89eb-b5e1-0022-a376bf41c165”) that is assigned by messageinterchange network 150 to the message. This unique session identifierenables tracking of the message through the routing network. The Tokenelement at line 5, on the other hand, is a unique reference identifier(i.e., “84e309b38c56a18cb9835203”) that enables message interchangenetwork 150 to uniquely identify a delivered message in the routingnetwork. This unique identifier serves as a message reference inresponse messages.

As further illustrated in Appendix B.2, the To element, at lines 6-12,includes the service identifier (i.e., “3340f32c035d7499”) for XpandiCoas well as the enrichment operation that is desired to be invoked.Specifically, at line 7, the purchase order message identifies the“zipPlus4” operation. The “zipPlus4” operation is an example of anenrichment operation, wherein a 5-digit zip code is expanded to a9-digit zip code.

After the “zipPlus4” enrichment operation is completed, XpandiCo service408 returns a response message to message interchange network 150. Thereturned response message is illustrated in Appendix B.3. As appears atline 19 of the message, the Zip child element of the Address element hasbeen modified to include a 9-digit zip code.

After XpandiCo service 408 returns a response message to messageinterchange network 150, the message is then forwarded by messageinterchange network 150 to the Transmatics (replaceElement) service 410.In general, Transmatics (replaceElement) service 410 provides across-reference ID mapping function. This function provides the abilityto relate sets of values from disparate data sources to each other.These related values are stored persistently by the cross-referenceservice 410 and can be substituted for each other whenever a messagetravels from one of the sources to another.

This cross-reference function is especially useful for relating key orID values of two independent data sources. For example, consider ascenario where two different services independently maintain a customercontact list for the same customer. In this case, it would be difficultfor each service to process a change message from the other without across-reference map because the receiving service would have no explicitway of knowing which record to update. By using cross-reference service410, however, the receiving service's record ID could be automaticallysubstituted for the sender's record ID, thereby enabling the receivingservice to easily process the message and update the correct record.

In one embodiment, a cross-reference map actually stores a set ofrecords for each service sharing a cross-reference map. Each record caninclude an arbitrary number of name/value pairs, although one of them isidentified as the key. Records from different services can then berelated to each other in one of two ways. In one method, differentservices can be related to each other explicitly by relating two keyname/value pairs from different services. In another method, servicescan be related to each other automatically by having the cross-referenceservice 410 process the response to a message as well as the originatingmessage.

As would be appreciated, the cross-reference map can be queried later byspecifying a specific service, key name, and key value. The extractedname/value pairs from all related records can then be used to transforma message.

In the example of FIG. 4, Transmatics service 410 is being called uponto perform a replaceElement operation on the CustomerNumber. After theCustomerNumber is replaced with a number that is recognized by The AcmeCompany, Transmatics service 410 returns a response message to messageinterchange network 150. As illustrated in Appendix B.5, the customerIDelement at line 23 has been changed to “BX0045012” from the previouscustomerID value of “3489.”

After the replaceElement operation has been performed by Transmaticsservice 410, the message is then forwarded to KeepEmOut.com service 412.KeepEmOut.com service 412 performs a message filtering service byensuring that The Acme Company will only receive messages fromauthorized entities. As such, KeepEmOut.com service 412 can be includedinto the routing list based on a routing script that has been defined byThe Acme Company.

If the message passes through KeepEmOut.com service 412, then themessage is finally delivered to The Acme Company service 404. An examplemessage as delivered to The Acme Company is illustrated in Appendix B.4.An example of a response message by The Acme Company to MyBiz.com isalso illustrated in Appendix B.5.

As thus described, message interchange network 150 enables flexibleinteraction with third-party services. The connection of thesethird-party services to an open platform enables enterprise customers toflexibly define their message transaction framework. As will bedescribed in greater detail below, message interchange network 150 canalso be used to enable flexible interaction between enterprise customersand their ASPs.

In general, the distribution of an enterprise's information among ASPsrequires a security framework by which each ASP can authenticate accessto that enterprise's information by another ASP. In apoint-to-point-messaging model, the conventional approach is to embedthe authentication information (encrypted) in the message itself or insome challenge protocol. In a collaborative environment, thisauthentication approach suffers several disadvantages. First, theoriginator of a message may be an ASP acting on behalf of an enterprise,and will therefore be unaware of the authentication credentials topresent to the recipient ASP. Second, the authentication credentials areapplicable only to the recipient ASP and do not authenticate access ofother services in the message's route. Third, many systems use standardHTTPS-based authentication, which requires synchronous invocation of therecipient. Polling for messages would therefore be disallowed. Finally,services along a message's route that operate on the message's contentshould not have visibility to the authentication information.

In accordance with the present invention, message interchange network150 authenticates each service that participates in a message's route.Message interchange network 150 can then provide an authentication tokenthat substitutes for an enterprise's authentication credentials. Theproposed token is an identifier (GCID) that represents an authenticatedservice to the enterprise's account with a specific ASP. An ASP thatreceives a GCID in a message only needs to authenticate messageinterchange network 150 since message interchange network 150 hasalready authenticated the message sender. The ASP can either have aninternal map between the GCID and enterprise account identifier, or canrequire the account identifier to accompany the GCID.

If the ASP does not want to maintain its own internal mapping between anenterprise's GCID and the enterprise's account, then the ASP wouldprovision the enterprise's account identifier to message interchangenetwork 150. Message interchange network 150 would then insert theaccount identifier with the GCID in any subsequent messages from theenterprise to ASP 620.

For both an enterprise and ASP to trust a GCID provided by messageinterchange network 150, the GCID should be validated by bothorganizations as representing the enterprise's account on the ASP.Setting up this trust relationship is accomplished through aprovisioning process that is completed prior to the routing of messagesbetween the enterprise and the ASP. The process of provisioning atrusted GCID in message interchange network 150 involves twoauthentication steps: the enterprise first authenticates itself tomessage interchange network 150 and receives a GCID, then the enterpriseauthenticates itself to the ASP and associates the GCID with theenterprise's account.

FIG. 6 illustrates an embodiment of the provisioning process. It shouldbe noted that in the illustrated embodiment of FIG. 6, it is assumedthat the enterprise and the ASP have already registered with messageinterchange network 150.

The provisioning process begins at step (1) where ASP 620 registers withmessage interchange network 150, alerting message interchange network150 that its service requires provisioning. In this process, ASP 620provides a URL to message interchange network 150. The provided URLenables an enterprise user 610 to logon to the ASP's website forprovisioning.

At step (2), enterprise user 610 logs in to the message interchangenetwork's web site. This authenticates enterprise user 610 with messageinterchange network 150. Enterprise user 610 then registers for a GCIDat step (3). This GCID will represent an authenticated entity that canboth send and receive messages through message interchange network 150.At step (4), enterprise user 610 selects a service from the messageinterchange network directory representing an ASP with whom theenterprise has an account.

At step (5), message interchange network 150 then automaticallyredirects enterprise user 610 to a website at ASP 620. In this process,message interchange network 150 sends the enterprise's GCID and aprovisioning token to the web page.

In one embodiment, message interchange network 150 passes a GCID, aprovisioning token, and a return URL as a query string in the ASP's URLusing three parameters: serviceID—an 8 byte hex number representing theGCID registered by an enterprise user; token—an 8 byte hex numberrepresenting a unique token to be returned in the confirmation messagefrom the ASP back to message interchange network 150; and returnURL—aURL string representing where the user should be redirected to aftercompleting the authentication and provisioning process at the ASPwebsite.

An example of a redirect URL would be:

-   -   https://www.asp.com/gc?serviceID=345023ba2300d353&token=459012c9a78b90af        &returnURL=https://www.grandcentral.com/provisioning/auth.jhtml

On the ASP's website, enterprise user 610 logs in to ASP 620 at step(6), thereby being authenticated by ASP 620. ASP 620 will then recognizethe validity of the GCID as representing enterprise 610. At step (7),the ASP's website can optionally allow enterprise user 610 to selectevents (if any) for which the ASP's service should send notificationmessages to the enterprise's GCID.

After authenticating enterprise user 610 and allowing enterprise user610 to select events, the ASP website redirects enterprise user 610 backto the message interchange network website at step (8). Next, at step(9), ASP 620 posts a message to message interchange network 150indicating that ASP 620 has accepted the enterprise user'sauthentication of the GCID. In one embodiment, the message contains boththe GCID and the provisioning token originally sent to the ASP's webpageby message interchange network 150. In general, this back-channelconfirmation, as opposed to returning a confirmation in a URL redirectback to message interchange network 150, prevents spoofing of theconfirmation.

In one embodiment, ASP 620 posts the confirmation message to messageinterchange network 150 using the message interchange network messagingprotocol. Message interchange network 150 would expect specific valuesin some of the message elements. An example of a confirmation message(showing only the relevant message elements) is shown below. As would beappreciated, the actual values of the arguments and document contentwould be dependent on the specific provisioning circumstances.

<Message>type=“request”> <Header> . . . <To><Service>name=“grandcentral/provisioning”> <Arguments> <![CDATA[<token>459012c9a78b90af</token> <gcid>63801c78327fd901</gcid><operation>name=“setPermission”> <parameter>include</parameter></operation> <operation>name=“setCookie”/> ]]> </Arguments> </Service></To> . . . </Header> <Body><Document>id=“COOKIE”>content-type=“text/xml”>encoding= “none”><![CDATA[ <!-->insert>enterprise>account>information>--> ]]> </Document></Body> </Message>

The values for the GCID and token parameters in the arguments should bethe values received via the web interface redirection. The cookieparameter (and the document in the message body) can be omitted from theconfirmation message if ASP 620 maintains the map between the GCID andenterprise account identifier. Otherwise, the contents of the documentelement should be whatever text or XML ASP 620 requires to determine theenterprise's account identifier.

In general, a service can register a block of text or XML (referred toas a cookie) that message interchange network 150 is to include with amessage whenever a message is delivered to the service. This cookie isanalogous to cookies in web browsers. An example of a cookie is accountinformation that a service requires when receiving a message fromparticular sources. This eliminates the need for the sender of a messageto include, or even be aware of, this information when sending themessage.

If enterprise user 610 fails authentication by ASP 620, ASP 620 shouldnot send a confirmation message to message interchange network 150. ASP620 should, however, provide immediate feedback to enterprise user 610on the web page that authentication failed.

After processing the confirmation message, message interchange network150 returns a status response to ASP 620. The status element in theresponse message will be absent in the case of a success and otherwisewill contain an error code.

In one embodiment, message interchange network 150 must receive theconfirmation message from ASP 620 within 24 hours after enterprise user610 initiates provisioning a GCID. If message interchange network 150does not receive the confirmation within that time period, then theprovisioning token will expire. If message interchange network 150receives a confirmation message after the token has expired, messageinterchange network 150 would not recognize the confirmation and wouldreturn an error back to ASP 620. If no confirmation is received, messageinterchange network 150 would not notify either ASP 620 or enterpriseuser 610 about the expiration of the provisioning token.

In an alternative embodiment of the provisioning process, ASP 620provides a launch point from its own website for provisioning. ASP 620could then redirect a user originally at the ASP site over to themessage interchange network site to register for a GCID. In thisembodiment, step (8) would not be necessary after message interchangenetwork 150 redirects the user back to the ASP's site.

It is a feature of the present invention that the provisioning processcan set up a trust relationship between the enterprise and the ASP. WhenASP 620 returns the provisioning confirmation message to messageinterchange network 150, ASP 620 is indicating that its service truststhe enterprise's GCID for sending messages and trusts all of theenterprise's GCIDs for receiving messages. Similarly, by thisprovisioning process, the enterprise is indicating trust of ASP 620 forsending and receiving messages.

It should be noted that if an ASP does not wish to expose the notion ofaccounts (i.e., messages to the ASP are not account-specific), or if theASP does not wish to exploit the message interchange network'sauthentication framework, then the ASP may choose not to requireauthentication of an enterprise's GCID to a specific account in the ASP,and this provisioning process is not required.

If ASP 620 wants to revoke the authenticated association between anenterprise's GCID and the enterprise's account in ASP 620, ASP 620 cansimply cease to recognize the association between the GCID and account.In this case ASP 620 would return an error response whenever it receivesa message from that GCID. ASP 620 can also use the message interchangenetwork website to unset permissions granted by ASP 620 to theenterprise. Message interchange network 150 would then not allow theenterprise's GCID to send messages to ASP 620.

Alternatively, ASP 620 can send a request message to message interchangenetwork 150 to revoke the previously provisioned permissions and cookie.In one embodiment, this message would contain the following information:

<Message >type=“request”> <Header > . . . <To ><Service>name=“grandcentral/provisioning”> <Arguments> <! [CDATA[<gcid>63801c78327fd901</gcid> <operation>name=“clearPermission”><parameter>include</parameter> </operation><operation>name=“clearCookie”/> ]]> </Arguments> </Service> </To> . . .</Header> <Body/> </Message>

The effect of this revocation message is that message interchangenetwork 150 automatically revokes all permissions granted by ASP 620 tothe enterprise, and message interchange network 150 removes the mappingof the enterprise's GCID to ASP's cookie in the message interchangenetwork registry.

After processing the revocation message, message interchange network 150returns a status response to ASP 620. The status element in the responsemessage is absent in the case of a success and otherwise will contain anerror code.

After an enterprise provisions a trusted GCID between an enterprise andan ASP's service, the GCID becomes a mapped service representing theASP's service specific to the enterprise's account. The followingscenarios illustrate how this GCID would be used in various messagingsituations.

First, assume that the enterprise wishes to send a message to the ASPspecific to the enterprise's account with the ASP. The enterprise shouldthen send a message to its mapped service for the ASP:

<Message> <Header> <From> <Service >gcid=“enterprise”/> </From> <To><service >gcid=“enterprise/mappedService”/> </To> </Header> </Message>

This would be translated by message interchange network 150 for deliveryto the ASP:

</Message> <Header> <From> <service>gcid=“enterprise/mappedService”/></From> <To> <Service >gcid=“asp/service”> <Cookie><![CDATA[account=12345]]></Cookie> </Service> </To> </Header> </Message>

It should be noted that the enterprise could send the message directlyto the ASP rather than to the mapped service, and the cookie would stillbe inserted correctly by message interchange network 150. The advantagefor the enterprise in sending the message to the mapped service ratherthan directly to the ASP is to facilitate a consistent tracking ofinvocations of the ASP whether from the enterprise or from another ASPon behalf of the enterprise.

In a second scenario, assume that an enterprise has accounts with morethan one ASP. When integrating the exchange of information between theseASPs, the enterprise may allow one ASP to send requests or notificationsto another ASP on behalf of the enterprise. With mapped services, theASPs do not actually need to know each other specifically. A first ASPwould send a message to the enterprise's service mapped to the secondASP:

<Message> <Header> <From> <Service>gcid=“asp1/Service”/> </From> <To><service>gcid=“enterprise/mappedService”/> </To> </Header> </Message>

This would be translated by message interchange network 150 for deliveryto the second ASP:

</Message> <Header> <From> <service>gcid=“enterprise/mappedService”/></From> <To> <Service>gcid=“asp2/service”> <Cookie><![CDATA[account=12345]]></Cookie> </Service> </To> </Header> </Message>

Note that the message as delivered to the second ASP hides the identityof the first ASP. In effect, message interchange network 150 effects avirtual proxy service in mapping between services. Accordingly, if themessage is a request, then the second ASP's response message would bereturned to the enterprise's mapped service and redirected to the firstASP.

Having described the flexibility in the operation of message interchangenetwork 150, an embodiment of message interchange network 150 is nowprovided with reference to FIG. 5. FIG. 5 illustrates a message routingnetwork 500 that includes clients 510, points of presence (POP) 520-n,and data center 530.

Clients 510 are generally assigned to a particular POP 520-n. POPs 520-ninclude a plurality of servers 522, a message queue 524, and a directorycache 526. Directory cache 526 includes profile information on clients510. The content of directory cache 526 is based on profile database 532in data center 530. Message queue 524 is operative to store messagesthat are posted by clients 510 and to store messages that are awaitingdelivery to clients 510. Finally, servers 522 are lightweight serversthat process HTTP transactions. Servers 522 are operative to receivemessages posted by clients 510, and to send messages to clients 510. Asnoted, clients 510 can have messages pushed to them or can retrievemessages as part of a polling process.

Routing within message routing network 500 is generally enabled throughrouters 531 in data center 530. In one embodiment, routers 531 areoperative to pull messages from message queues 524 in POPs 520-n,perform route calculations, and post messages to message queues 524 thatare located in a POP 520-n that is assigned to the destination client510.

Headers of messages that are routed by routers 510 are stored in messagedatabase 533. Message database 533 retains updated states of messageobjects that are routed through message routing network 500.

Also included within data center 530 is profile database 532, datawarehouse 535, and web interface component 534. Profile database 532stores profile information for registered clients 510. The profileinformation includes routing rules that have been defined for thevarious clients 510. Data warehouse 535 stores a collection of loginformation relating to messages that are processed by message routingnetwork 500. Finally, user interface component 534 enables clients 510to enter profile information into profile database 532, access reportsin data warehouse 535, and perform directory lookups to find otherconnected services.

While the invention has been described in detail and with reference tospecific embodiments thereof, it will be apparent to one skilled in theart that various changes and modifications can be made therein withoutdeparting from the spirit and scope thereof. Thus, it is intended thatthe present invention cover the modifications and variations of thisinvention provided they come within the scope of the appended claims andtheir equivalents.

Appendix A - Example Messages and Message Elements I. Messages PostedRequest and Notification Messages <Message> <Header> <To/> <From/><Topic/>? <Expiration/>? </Header> <Body> <Document />* </Body></Message> Posted Response Messages <Message> <Header> <Token/> <From/><Status/>? </Header> <Body> <Document/>* </Body> </Message> DeliveredRequest and Notification Messages <Message> <Header> <Session/> <Token/><To/> <From/> <Topic/>? </Header> <Body> <Document/>* </Body> </Message>Delivered Response Messages <Message> <Header> <Session/> <Token/> <To/><From/> <Topic/>? <Status/>? </Header> <Body> <Document />* </Body></Message> II. Message Elements <Message> Purpose: Root envelope for amessage. Message types: All message types. Attributes: type (required) =request | response | notification test (optional) = false (default) |true Child Elements: Header-{1}, Body-{1} Note: The test attributeindicates if the message is a test message - that the message should berouted with no persistent effects in any of the participating services.The message type is “request” when a message is delivered to an engine.<Header> Purpose: Root element for a message header. Message types: Allmessage types. Attributes: None. Child Elements: Session, Token, To,From, Topic, Status, Expiration {Cardinality of elements depends onmessage type} <Session> Purpose: Unique session identifier assigned bymessage interchange network to the message. Message types: All deliveredmessage types. Attributes: id (required) = (globally uniqueidentification string) Content: None. Note: The session is effectively a“tracking slip” for messages. In one embodiment, all services in amessage's route receive the same session identifier. The scope of amessage session depends on the message type. For a request message, themessage session includes the response as well - therefore responsemessages do not receive a new session. For a notification, the messagesession only applies through to the recipients. In an alternativeembodiment, a service can demand a new session for an included service,thereby hiding some services from being tracked by the original sender.<Token> Purpose: Unique reference identifier assigned by the messageinterchange network. Message types: All delivered message types. Postedresponse. Attributes: value (required) = (unique identification string)Content: None. Note: A token is used to uniquely identify a deliveredmessage when issuing an acknowledge to polled delivery, and serves as amessage reference in posted response messages. When a service posts aresponse message, the message includes the token from the previouslyreceived request message. <To> Purpose: Identification of the recipientsof the message. Message types: All message types except posted response.Attributes: None. Child Elements: Service-{1:N} Note: The To elementindicates the recipients of a posted request or notification message. Indelivered messages, the To element indicates the service invoked andcontains the arguments and cookie necessary for the service to processthe message. Posted request and notification messages may have multiplerecipients, in which case there will be multiple child Service elements.All delivered messages can include only one Service element. <Service>Purpose: Identifies a service connected to the message interchangenetwork Message types: All message types. Attributes: gcid = (uniqueservice identifier assigned by the message interchange network to theservice); name = (name of organization owning the service)/(servicename) Child Elements: Arguments-{0:1}, Cookie-{0:1} Note: At least oneof the two attributes should appear in order to specify the service. Ifone of the attributes is omitted, the message interchange network fillsin the omitted attribute when composing a header for delivery.<Arguments> Purpose: Text or parameters that further specifies what theservice is to perform and how. Message types: All message types.Attributes: None. Content: Text string (as xml CDATA block). Note: Theformat of the argument string is up to each service to define. TheArguments element need not be parsed or verified by the messageinterchange network. It is the responsibility of the message composer toinsert the necessary contents understandable by the service. Whether ornot the text is XML, the contents of the Arguments element should beenclosed in a CDATA block. <Cookie> Purpose: Service-defined block oftext or parameters that a service wants delivered with invocation.Message types: All message types. Attributes: None. Content: Text string(as xml CDATA block). Note: The cookie element contains a block of text(or xml) previously registered by a service with the message interchangenetwork. The format of the cookie string is up to each service todefine. The Cookie element need not be parsed or verified by the messageinterchange network. Whether or not the text is XML, the contents of theCookie element will be enclosed in a CDATA block. <From> Purpose:Identification of the sending (or invoking) service of the message.Message types: All message types. Attributes: None. Child Elements:Service-{1} Note: The From element indicates the sender of the messageto the receiving services. In the delivery header, the service in theFrom element is the “logical” sender representing the service thatincluded the receiving service into the message route. Thus, eachreceiving service perceives the received message as an invocation fromthe including service rather than a message coming from the originatingsender service. <Topic> Purpose: Indicate the topic of the message.Message types: All message types except posted response. Attributes:None. Content: Dot-separated topic category. Note: Topic provides acategorization of the message. The categorization should behierarchical, but the message interchange network need not have apredefined set of topics. The Topic element is useful for services thatpush out events, where the topic can be the name of the event for whichrecipients are being notified. <Status> Purpose: Indicates the status ofprocessing a request. Message types: Response. Attributes: None.Content: Dot-separated status code. Note: The status element provides ameans for the respondent of a request message to indicate the success(or lack thereof) of processing the request message. Absence of thestatus element in a response message indicates unqualified success ofthe response. In the case of a qualified success (e.g., a warning, afault, a failure, or other status), a service should include the statuselement and provide an appropriate status code indicating the problem.<Expiration> Purpose: Specifies a time by which a message must completeits routing. Message types: Posted request and notification. Attributes:units (optional) = msec (default) | sec | hr Content: numeric value.Note: The expiration specifies when the message must reach its finaldestination. For request messages, the expiration includes the return ofthe response message. For notification messages, the expiration onlyapplies up to delivery to the recipients. Expiration time is measuredagainst the time the message is first posted to the message interchangenetwork. <Body> Purpose: The root element for the actual message data.Message types: All message types. Attributes: None. Child Elements:Document-{0:N} <Document> Purpose: A self-contained unit of messagedata. Message types: All message types. Attributes: id (optional) =(fragment name for document element); content-type (required) = (MIMEtype); schema (optional) = (URI to schema used for document; nodefault); xmlns (optional) = (URI to namespace used in document; nodefault); encoding (optional) = none (default) | base64 Content: Thedocument data - XML, binary, free text, or any other format.

APPENDIX B.1 Message as posted by MyBiz.com  1<Message>xmlns=“http://namespaces.grandcentral.com/messages/env−v01” 2 >type=“request”>test=“false”>  3 <Header>  4 <To>  5<Service>name=“TheAcmeCompany/Supply”>  6 <Arguments>  7<![CDATA[action=ProcessPurchaseOrder]]>  8 </Arguments>  9 </Service> 10<Service>name=“BigBrother/GlobalListener”/> 11 </To> 12 <From> 13<Service>gcid=“386b4520f489c217”/> 14 </From> 15<Expiration>units=“hr”>20</Expiration> 16 </Header> 17 <Body> 18<Document>id=“doc−1”>content-type=“text/xml”>encoding=“none”> 19<PurchaseOrder>xmlns=“urn:MyBiz:ns−1”> 20 <Id>89987</Id> 21<Item>type=“SKU”>3456-76987-34</Item> 22 <Quantity>2</Quantity> 23<CustomerNumber>3489</CustomerNumber> 24<Address>31>Ocean>Front>Way,>SomeCity,>AK,>10984</Address> 25</PurchaseOrder> 26 </Document> 27 </Body> 28 </Message>

Appendix B.2 - Message as Delivered to XpandiCo 1<Message>xmlns=“http://namespaces.grandcentral.com/messages/env-v01”2 >type=“requests”> 3 <Header> 4<Session>id=“34b9f6d0-89eb-b5e1-0022-a376bf41c165”/> 5<Token>value=“84e309b38c56a18cb9835203”/> 6 <To> 7<Service>gcid=“3340f32c035d7499”>name=“xpandico/zipPlus4”> 8 <Arguments>9 <![CDATA[element=PurchaseOrder/Address/Zip]]> 10 </Arguments> 11</Service> 12 </To> 13 <From> 14<Service>gcid=“386b4520f489c217”>name=“mybiz.com”/> 15 </From> 16</Header> 17 <Body> 18<Document>id=“docA”>content-“type=“text/xml”>encoding=“none”> 19<PurchaseOrder>xmlns=“http://www.estandards.org/PurchaseOrderRequest”>20 <POId>89987</POId> 21 <Item>type=“SKU”>3456-76987-34</Item> 22<Quantity>2</Quantity> 23 <CustomerID>3489</CustomerID> 24 <Address> 25<Street>31>Ocean>Front>Way</Street> 26 <City>SomeCity,>AK</City> 27<Zip>10984</Zip> 28 </Address> 29 </PurchaseOrder> 30 </Document> 31</Body> 32 </Message>

Appendix B.3 - Response Message as Returned from XpandiCo 1<Message>xmlns=“http://namespaces.grandcentral.com/messages/env-v01”2 >type=“response”> 3 <Header> 4<Token>value=“84e309b38c56a18cb9835203”/> 5 <From> 6<Service >name=“xpandico/zipPlus4”/> 7 </From> 8 </Header> 9 <Body> 10<Document>id=“xfm-doc”>content-type=“text/xml”>encoding=“none”> 11<PurchaseOrder>xmlns=“http://www.estandards.org/PurchaseOrderRequest”>12 <POId>89987</POId> 13 <Item>type=“SKU”>3456-76987-34</Item> 14<Quantity>2</Quantity> 15 <CustomerID>3489</CustomerID> 16 <Address> 17<Street>31>Ocean>Front>Way</Street> 18 <City>SomeCity,>AK</City> 19<Zip>10984-0673</Zip> 20 </Address> 21 </PurchaseOrder> 22 </Document>23 </Body> 24 </Message>

Appendix B.4 - Message as Delivered to The Acme Company 1<Message>xmlns=“http://namespaces.grandcentral.com/messages/env-01”2 >type=“request”> 3 <Header> 4<Session>id=“34b9f6d0-89eb-b5e1-0022-a376bf41c165”/> 5<Token>value=“30c481b28ad6e87b09f62182”/> 6 <To> 7<Service>gcid=“789e3223d9017f45”>name=“TheAcmeCompany/Supply”> 8<Arguments> 9 <![CDATA[action=ProcessPurchaseOrder]]> 10 </Arguments> 11</Service> 12 </To> 13 <From> 14<Service>gcid=“386b4520f489c217”>name=“mybiz.com”/> 15 </From> 16</Header> 17 <Body> 18<Document>id=“doc-3”>content-type=“text/xml”>encoding=“none”> 19<PurchaseOrder>xmlns=“http://www.estandards.org/PurchaseOrderRequest”>20 <POId>89987</POId> 21 <Item>type=“SKU”>3456-76987-34</Item> 22<Quantity>2</Quantity> 23 <CustomerID>BX0045012</CustomerID> 24<Address> 25 <Street>31>Ocean>Front>Way</Street> 26<City>SomeCity,>AK</City> 27 <Zip>10984-0673</Zip> 28 </Address> 29</PurchaseOrder> 30 </Document> 31 </Body> 32 </Message>

Appendix B.5 Response Message to MyBiz.com as Posted by The Acme Company1 <Message>xmlns=“http://namespaces.grandcentral.com/messages/env-v01”2 >type=“response”> 3 <Header> 4<Token>value=“30c481b28ad6e87b09f62182”/> 5 <From> 6<Service>name=“TheAcmeCompany/Supply”/> 7 </From> 8 </Header> 9 <Body>10 <Document>id=“resp_doc”>content-type=“text/xml”>encoding=“base64”> 11zs134rkuwkloirlmnm5loli2smn7fslk7ui88u98wq7rsdolikjhdfloi9rkjjf 12</Document> 13 </Body> 14 </Message>

1. A method for routing application-level messages in a message routingnetwork, comprising: (a) providing a message routing network forexchanging application-level messages between a plurality of services,said message routing network being built on an open platform overlayinga public network and managing said plurality of services, each of saidservices being accessible by others of said plurality of servicesaccording to properties and permissions associated with each service insaid plurality of services; (b) invoking a first service among theplurality of services during a logical routing of an application-levelmessage in said message routing network, said logical routing allowingsaid first service to modify a route or a context for said messagewithout said message being physically delivered to said first service,said first service invocation having a first context; and (c) invoking asecond service among the plurality of services during said logicalrouting of said message in said message routing network, said logicalrouting allowing said second service to modify a route or a context forsaid message without said message being physically delivered to saidsecond service, said second service invocation having a second contextthat is defined at least in part by said first service; said logicalrouting determined by an evaluation of routing scripts defined byindividual ones of said plurality of services such that each of saidservices is capable of including one or more others of said plurality ofservices in said logical routing without being included in a route forphysical delivery of said message.
 2. The message routing method ofclaim 1, wherein a context to an invocation includes an identity of aninvoker service.
 3. The message routing method of claim 1, wherein acontext to an invocation includes arguments to an invoked service. 4.The message routing method of claim 1, wherein a context to aninvocation includes a session identifier for said message.
 5. Themessage routing method of claim 1, wherein a context to an invocationincludes a topic for said message.
 6. The message routing method ofclaim 1, wherein a context to an invocation includes billingresponsibility for said invocation.
 7. The message routing method ofclaim 1, wherein said message routing network controls at least part ofan invocation.
 8. The message routing method of claim 1, wherein acontext of an invocation is included at least in part in a headerelement of a message.
 9. The message routing method of claim 1, whereina context of an invocation is included at least in part in a bodyelement of a message.
 10. The message routing method of claim 1, whereina context of an invocation is included at least in part in an attachmentof a message.
 11. The message routing method of claim 1, furthercomprising restoring said context, upon return from said second serviceinvocation, to said first context.
 12. The message routing method ofclaim 1, further comprising adding a returned context from said secondservice invocation to said restored context.
 13. A computer programproduct, stored on a machine-readable medium, comprising instructionsoperable to cause a computer to: invoke a first one of a plurality ofservices during a logical routing of an application-level message in amessage routing network, said message routing network being built on anopen platform overlaying a public network and managing said plurality ofservices, each of said services being accessible by others of saidplurality of services according to properties and permissions associatedwith each service in said plurality of services, said logical routingallowing said first service to modify a route or a context for saidmessage without said message being physically delivered to said firstservice, said first service invocation having a first context; andinvoke a second service during said logical routing of said message insaid message routing network, said logical routing allowing said secondservice to modify a route or a context for said message without saidmessage being physically delivered to said second service, said secondservice invocation having a second context that is defined at least inpart by said first service; said logical routing determined by anevaluation of routing scripts defined by individual ones of saidplurality of services such that each of said services is capable ofincluding one or more others of said plurality of services in saidlogical routing without being included in a route for physical deliveryof said message.
 14. A message routing system, comprising: a messagerouting network that enables routing of application-level messagesbetween a plurality of services, said message routing network beingbuilt on an open platform overlaying a public network and managing saidplurality of services, each of said services being accessible by othersof said plurality of services according to properties and permissionsassociated with each service in said plurality of services, wherein saidrouting is based on a logical routing of a message that is effectedthrough a sequence of invocations among said plurality of services, saidlogical routing allowing said services to modify a route or a contextfor said message without the message being physically delivered to oneor more of the services among the plurality of services, wherein acontext of an invocation is defined at least in part by an invokingservice, wherein upon return from a service invocation, said messagerouting network restores a message context to a context state of aninvoking service of said service invocation, said logical routingdetermined by an evaluation of routing scripts defined by individualones of said plurality of services such that each of said services iscapable of including one or more others of said plurality of services insaid logical routing without being included in a route for physicaldelivery of said message.
 15. The message routing system of claim 14,wherein a context of an invocation is defined at least in part by aheader of a message.
 16. The message routing system of claim 14, whereina context to an invocation includes an identity of an invoker service.17. The message routing system of claim 14, wherein a context to aninvocation includes arguments to an invoked service.
 18. The messagerouting system of claim 14, wherein a context to an invocation includesa session identifier for said message.
 19. The message routing system ofclaim 14, wherein a context to an invocation includes a topic for saidmessage.
 20. The message routing system of claim 14, wherein a contextto an invocation includes billing responsibility for said invocation.21. The message routing system of claim 14, wherein said message routingnetwork controls at least part of an invocation.
 22. The message routingsystem of claim 14, wherein said logical routing occurs prior to aphysical routing of a message.
 23. The message routing system of claim14, wherein at least part of said logical routing occurs afterinitiation of a physical routing of a message.
 24. The message routingsystem of claim 14, wherein physical routing of a message occurs atidentified points during said logical routing.
 25. The message routingsystem of claim 14, wherein a context of an invocation is included atleast in part in a header element of a message.
 26. The message routingsystem of claim 14, wherein a context of an invocation is included atleast in part in a body element of a message.
 27. The message routingsystem of claim 14, wherein a context of an invocation is included atleast in part in an attachment of a message.
 28. A message routingmethod for routing application-level messages between a plurality ofservices, comprising: (a) providing a message routine network forexchanging application-level messages between a plurality of services,said message routine network being built on an open platform overlayinga public network and managing said plurality of services, each of saidservices being accessible by others of said plurality of servicesaccording to properties and permissions associated with each service insaid plurality of services; (b) evaluating routing scripts defined byindividual ones of said plurality of services to determine a logicalrouting of an application-level message such that each of said servicesis capable of including one or more others of said plurality of servicesin said logical routing without being included in a route for physicaldelivery of said message; (c) invoking a first service that receivesonly logical delivery of said message, said logical delivery allowingsaid first service to modify a route or a context for said messagewithout said message being physically delivered to said first service,wherein said first service invocation has a first context defined atleast in part by a first invoking service; (d) invoking a secondservice, said second service invocation having a second context that isdefined at least in part by said first service, wherein said secondservice invocation is managed by a message routing network on behalf ofsaid first service; and (e) delivering said message having said secondcontext to said second service over said public network.
 29. The messagerouting method of claim 28, wherein a context of an invocation isdefined at least in part by a header of a message.
 30. The messagerouting method of claim 28, wherein a context to an invocation includesan identity of an invoker service.
 31. The message routing method ofclaim 28, wherein a context to an invocation includes arguments to aninvoked service.
 32. The message routing method of claim 28, wherein acontext to an invocation includes a session identifier for said message.33. The message routing method of claim 28, wherein a context to aninvocation includes a topic for said message.
 34. The message routingmethod of claim 28, wherein a context to an invocation includes billingresponsibility for said invocation.